1. Field of the Invention
The present invention relates to a door controlling mechanism, and more particularly but not by any way of limitation, to a longitudinal-slide door controlling mechanism adapted for large vehicles, such as buses, to save space-occupied caused by the conventional rotary door and to eliminate the passerby-struck during opening.
2. Related Art
A bus is a road vehicle designed to carry passengers. Buses have a capacity as high as 300 passengers. The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are used for longer distance services. Buses may be used for scheduled bus transport, scheduled coach transport, school transport, private hire, tourism; promotional buses may be used for political campaigns and others are privately operated for a wide range of purposes.
As is generally well known in the art, a rotary door mainly used in the buses. These rotary doors are available in two distinct types, commonly referred to as zero-lead and lift-and-lock. Either door operator type can be adapted for use with pneumatic or hydraulic fluids. Both rotary door types have a double acting cylinder typically attached to a flanged mounting bracket. The mounting bracket has an aperture for an output shaft which is attached at one end to the piston disposed with the double acting cylinder and coupled with a door post at a distal end. A cover is generally provided for encasing the double acting cylinder as well as any other rotary door operator components attached either to the double acting cylinder or to the mounting bracket.
When the rotary is operated to open, the door is rotated. If the operator, such as the bus drivers, is careless, the rotating door may strike passerby, bikes, cars or objects on the roadside. The passerby may be injured. The bikes, cars or the doors would be damaged. Also, when the door is completely opened, the door is moved to one side of the entrance. Part of the space of the entrance is occupied by the door. Therefore, the entrance has to be larger to make enough space for the passengers. The space-used in the car would be decreased.